What should you know about dark spots on hands suddenly?

Think back to the days before the colour appeared: a burn, cut, bite, rash, new soap, chemical exposure, or repeated friction can leave post-inflammatory hyperpigmentation. Sun exposure can make existing pigment more visible, and sun spots may develop on exposed skin over time. A spot that is truly new without an obvious trigger needs a closer look rather than a guess.

Note the exact onset, whether more spots are appearing, and whether the area is flat, scaly, painful, itchy, swollen, or bleeding. Take a clear photograph beside a familiar object for scale and avoid repeatedly rubbing or scraping the mark.

Stop any product that stings or was introduced shortly before the change. Rinse off suspected irritants, moisturise gently, and protect the hands from sunlight with sunscreen and covering. Do not apply household acids, strong bleaching agents, or leftover prescription creams.

If the colour remains, spreads, or has no clear trigger, arrange a dermatology review. Once the cause is clear, treatment might involve a skin brightening treatment, chemical peel, or picosecond laser treatment, but procedures are not a substitute for diagnosing a new lesion.

Seek prompt medical assessment for rapid enlargement, an irregular outline, multiple colours, a raised or firm surface, bleeding, crusting, persistent pain, or a sore that does not heal. Urgent advice is also sensible if sudden pigment change occurs with facial swelling, breathing difficulty, blistering, or a widespread reaction after a product or medicine.

Ask whether the mark could be post-inflammatory pigment, whether a dermatoscope examination or sample is needed, and whether a recent product or medicine is relevant. Ask which warning changes should trigger an earlier review.